At the same time, insider killings by uniformed Afghans against their foreign allies rose dramatically, the Associated Press figures showed. The insider attacks eroded confidence between the two sides at a crucial turning point in the war and when Nato troops and Afghan counterparts were in closer contact.

A Nato spokesman, US Air Force Lieutenant Colonel Lester T Carroll, said: "The overall situation is improving." He singled out Afghan special forces as "surgically removing insurgent leaders from the battle space".

General Mohammad Zahir Azimi, spokesman for the Afghan Ministry of Defence, said Afghan forces are now charged with 80% of security missions and are less equipped to face the most lethal weapon of the militants - roadside bombs. "Our forces are out there in the battlefields and combat areas more than at any other time in the past," he said, citing reasons for the spike in casualties.

US troop deaths, overall Nato fatalities and Afghan civilian deaths all dropped as insurgent attacks fell off in their traditional strongholds in the country's south and east. However, insurgent activity was up in the north and west, and overall levels of violence were higher than before a US troop surge two years ago.

US troop deaths declined overall from 404 last year to 295 deaths as of Saturday December 29, as Washington draws down its forces in the country. The Defence Department said 1,701 US troops had been killed in action in Afghanistan since the US invasion in 2001 until December 26. Of those, 338 died from non-hostile causes. Some 18,154 were wounded.

A total of 394 foreign troops including the Americans were killed this year, down from 543 last year. The British, with the second largest military presence, had 43 killed - the second highest toll among countries with forces in Afghanistan, by AP's count.

The AP keeps daily tallies of casualties and violent incidents across Afghanistan based on reports from Nato and Afghan officials. Most cannot be independently verified and other incidents may never come to light. The statistics sometimes vary from official counts because of time lags, different criteria and other reasons.

Deaths from so-called insider attacks - Afghan police and troops killing foreign allies - surged to 61 in 45 attacks, up from 35 last year. The number, provided by the Nato command, does not include the killing of an American civilian adviser on December 24 by a female member of the Afghan police because the investigation is continuing.

The focus of Nato's mission has largely veered from the battlefield to training the Afghans ahead of a pullout of most troops by 2014. The US plans to maintain a residual force the size of which is being determined.